Crank-shaft-lapping machine



April30, 1929. s. PLAYER CRANKSHAFT LAPPING MACHINE Filed June 17, 1925' 4 Sheets-Sheet S. PLAYER April 30, 1929.

CFANKSHAF'T LAPPING MACHINE MM M O 6 M o J; h, Mm when Q who hm Qw Q. Q o M 0 M R m N QM Q l MA N A S b 8 WWW q m: m & k NM mm 0 O H W April 30, 1929. 5 PLAYER 1,711,061

CRANKSHAFT LAPPING MACHINE Filed June 1'7, 1925 4 Sheets-Sheet 3 '7 3 a 5 I f z 4 15 0457 pfgyer Wa M April 30, 1929. 5', PLAYER 1,711,061

CHANT (SHAFT LAPPING MACHINE Filed June 17, 1925 4 Sheets-Sheet 4 @0479 I /g er the work.

Patented Apr. 30, 1929.

UNITED STATES PATENT OFFICE.

SYDNEY PLAYER, OF WESTIBORO, MASSACHUSETTS, ASSIGNOR TO NORTON COMPANY,

OF WORCESTER, MASSACHUSETTS, .A. CORPORATION OF MASSACHUSETTS.

CRANK-SHAFT-LAPPING MACHINE.

Application filed June 17, 1925. Serial No. 37,847.

This invention relates to a machine for lapping the main'bearings and the crankpins of crankshafts such as are used in automobile engines and for other similar purposes. 'It is necessary that these hearings be brought accurately to size and that they be given a substantially perfect circular section and it is also necessary that the surface be lapped or polished to a high degree of finish.

It is the object of my invention to provide a machine in which the several crankpins of a multi-throw shaft may be simultaneously lapped to a desired size and finish while the shaft is rotated upon its main axis.

In the preferred form of my invention, I also provide means for lapping the main bearings at the same time that I lap the crankpins.

A further feature of my invention relates to the provision of means for reciprocating the work relative to the lapping devices axially during the lapping operation and in non-coincidental relation to the rotation of The lapping devices which engage the bearings are also of novel construction and form a very important feature of my invention, particularly in the provison of means for positively clamping the separable parts-of the lapping devices in non-yielding contact with the work.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particu larly pointed out in the appended claims.

A preferred form ofihe invention is shown in the drawings in which r Fig. 1 is a front elevation of my improved lapping machine;

Fig. 2 is a plan view thereof;

Figs. 3 and 4 are sectional end elevations, taken along the lines 33 and 44 respectively in Fig. 1:

Fig. 5 is a longitudinal sectional elevation of the tail center of the machine;

Fig. 6 is a side elevation of one of the lapping devices;

Fig. 7 is a similar view, but showing some of the parts in a different position;

Fig. 8 is a sectional rear elevation, taken along the line 88 in Fig. 6; e

Fig. 9 is an enlarged sectional front elevation, taken along the line 9-9 in Fig. 6;

Fig. 10 is an enlarged side elevation of a pivotal connection in one of the lapping devices;

Fig. 11 is a sectional plan View, taken along Y the line 11-11 in Fig. 10; and

Fig. 12 is a detail sectional along the line 12-12 in Fig. 6.

Referring to the drawings, my improved crankshaft lapping machine comprises a frame or bed supported at its opposite ends upon bases 21 and 22 within which certain of'the operating mechanism is housed. A head stock 23 is mounted at one end of the bed 20 and a tail stock 24 is slidable along guide-ways 25 (Fig. 3) projecting upward from the bed 20. The head stock 23 is also preferably clamped to the same guide-ways but may be otherwise secured to the base if desired.

A driving spindle 26 (Fig. 1) is rotatable in hearings in the head 23 and is provided with a pulley 27 for a driving belt 28. The belt 23 extends downward and rearward through the bed 20 and base 21 to a driving pulley 29 one main drive shaft 30. The shaft 30 extends lengthwise of the machine between the bases 22 and 21 and is supported in self-aligning bearings 31 and 32 therein. A main driving pulley 33 is loosely mounted upon the shaft 30 and is continuously rotated by a drive belt 34. The pulley 33 may be conview, taken nected to the shaft 30 by means of a friction clutch 35 controlledby a forked arm 36 secured to a shipper rod 37 which is slidable axially by means of a shipper handle 38 pivoted at 39 to the base 22. The shipper handle 38 projects upward and forward through an opening 40 in the front of the bed 20 and is conveniently accessible by the operator.

The spindle 26 is commonly provided with a live center 41 for the work and with a driving pin 42 for rotating the same. The opposite end of the work is supported upon a center 43 seated in the end of a tubular men1- her 44 (Fig. 5) which is rotatably mounted in a sleeve 46, being preferably supported b y anti-friction bearings 47 and 48 therein. These bearings are separated bya spacer tube 45. The sleeve 46 is slidably mounted in the tail stock 24, which tail stock is made int-wo' parts as clearly shown in Fig. 3 and is pro-- vided with a recess 49 (Fig. 5). The sleeve 46 has a flange or ring 50 surrounding the sleeve and positioned within the recess 49. A heavy coil spring filsurrounds the sleeve 46 within therecess 49 and yieldingly moves the sleeve 46 toward the left, as viewed in Figs. 1 and 5. A ring 52 is threaded on the end of the sleeve 46 and engages an end surface of the tail stock 24 to limit such yielding movement.

A rope or cable 53 is secured at one end i to the tubular member 44 within the sleeve 46 and passes over guide ulleys 54- and 55 (Figs. 1, 2 and 3) to a foot ever 56 which extends forward to the front of the machine, where it 'rnay be conveniently depressed by, the operator to withdraw the tail center against the pressure'of the spring 51. When the pressure is removed, the tail center 43 advances to engage the work and to hold the work firmly against the head center 41.

When the tail center is adjusted to any substantial extent along the guidewa s 25, the cable 53 may be shortened or lengt ened to maintain the operative connection with the 7 foot lever 56. A weight 57 at the rear end for this purpose I provide a grooved member 60 fast on the spindle 26, adapted to receive rolls 61 (Fig. 4) mounted on a forked lever 62 ivote'd at 63 (Fig. 1 and having a latera 1y projecting arm 64 connected by a link 65 to a crankpin 66. The link 65 has a swivel connection to the arm 64 at its upper end and to a head 67 at its lower end, the head 67 providing the bearing upon the crankpin 66.

The crankpin 66 is mounted in guide-ways 68 (Fig. 4) in a disc 69 which is rotatable with a sprocket wheel 70 on a stud 71 (Fig. 1) secured to the base 21. The sprocket 70 is connected b a chain 72 to a sprocket 73 on the main drive shaft 30. Through these connections the work is reciprocated axially at the same time that it is rotating u on its centers 41 and 43 and the amount 0 reciprocation may be adjusted as desired by means of an adjusting screw 74 by which the stud 66 may be adjusted along the guide-ways 68 in --the disc 69. This reciprocation of the work during rotation thereof is avery important feature of my invention.

Having described the mechanism for supporting, rotating and reciprocating the work,

I will now describe the lapping devices by which the bearings are given a finished surface. For this purpose'I have mounted frame members 75 and 76 (Figs. 3 and 4) at the f upper rear portion of the machine, said frame members supforrtinga a pair of fixed cross shafts 77 an ach ofthese shafts is provided with a series of sleeves or bushings 80 (Fig. 12) having bearing inserts 81 at the 7 ends thereof and freely rotatable upon the supporting shafts 77 and 78. Collars 82 (Fig. 2) at each end of each series of bushings prevent axial movement of the bushings, while they are left free to rotate upon the shafts.

A series of depending arms 84 are provided with hubs 85 loosely fitting the bushings 80 and movable axially thereof. These arms 84 are secured in fixed position upon the bushings by set screws 86 in the hubs 85 or in any other convenient manner. Oil tubes 87 (Fig. 12) may be provided for the bushings 80 if found desirable. ,Each oil tube communicates with one of the recesses 88 within the bushings, formed between the bearing inserts 81, and each recess 88 communicates through an opening 89 inthe lower part of the bushing to a passage 90 extending downward through the depending arm 84.

A lap holder 91 (Fig 6) is pivoted to the lower end of each arm 84. The details of construction of the pivotal connection of these parts are best shown in Figs. 10 and 11, which indicate that the rear end of the holder 91 is forked at 92 to receive the lower end 93 of the arm 84. A hearing bushing 94 extends through the parts 92 and 93 and is held in position by adjustable take-up caps 95 and 96, threaded to the opposite ends of a stud 97. The cap 95 is preferably held from rotation by a pin 98 and the cap 96 is held in adjusted position by a screw 99 which may be inserted in any one of a series of holes in-the cap 96 and which is threaded into one of the forked ends 92 of the holder 91. A series of holes 92 are provided in the end 92, having a slightly different angular spacing than the holes in the cap 96. A very close or Vernier adj ustment of the bearing may thus be obtained. This bearing is lubricated by oil which is conducted downward through the oil passage 90 in the arm 84, as previously described.

Each lap holder 91 is provided at its front end with a cross bar 100 having pivots 101 for a pair of lovers 102 and 103 upon which the laps are supported. At their rear ends, the levers l02103 are connected by toggle links 104 and 105, and the link 105 is extended beyond its pivot at 107, where it is provided with a handle 108. The adjacent ends of the links 104 and 105 are connected by a stud 109 which projects into a slot 110 in the holder 91. The stud and slot limit movement of the toggle links in both directions.

When the parts are in the position shown in Fig. 6, the lapping members are forced the lapping members separated for removal from the finished work.

A pair of lapping members 112, 113, are mounted in ,the'forward ends of the levers 102 and 103. The lower lappingmember 112 is seated against a fiat surface 114 on the lever 102 and is centered thereon by a stud 115 secured in the lap and projecting downward I movement is limited by a pin 116 projecting into a slightly larger opening 117 in the lever 102.

The upper lap 113 has a swivel connection to the ball-shaped lower end of a stud 120 threaded in the end of the lever 103 and secured in adjusted position therein by a lock nut 121. A small. pin 121 (Fig. 6) holds the upper lap from dropping off the stud 120 when the lap is raised. An oiling device 122 may also be mounted on the forward end of the lever 103 and may be provided with an oil tube 123 extending downward into an enlarged oil opening 124. The lap 113 thus receives a supply of oil from the oiling device 122 but is left free to swivel and adjust itself about the end of the stud 120.

Referring to Fig. 6, it wi ll be seen that the laps do not cover the entire circumference of the bearing P, but are spaced a substantial distance apart. This spacing is found very advantageous in operation.

The lapping members 112 and 113 are preferably recessed at their central portions, as indicated at 130 in Fig. 9. This recess is provided for equalizing the lapping action upon the work and preferably the width of the recess 130 is equal to one half of the lapping surface 131 at each side of the recess or to one fifth of the Width of the entire lapping member. The travel of the lap on the bearing is also preferably about equal to the width of one of the lapping surfaces 131, or twice the width of the recess 130.

When the laps are thus recessed, it is found that the lap acts substantially uniformly throughout its whole path of travel and the results are much more satisfactory than when a solid and continuous lap is provided. A felt pad or wiper may be placed in the recess 130 to receive the oil from the oiler 122.

The holders 91 are also provided with splash guards 91 which protect the pivotal connections .of the holders to the arms 84 from any material thrown off from the laps as the crankshaft is rotated.

A fixed cross rod 140 extends between the frame members 7 5 and 76 and forms a rest for the lap holders when inoperative. Each lower lever 102 of the holder is notched at 102 (Fig. 6) to receive the rod 140.

Having thus described the construction of my improved crankshaft lapping machine, I-will now indicate briefly the method of operation thereof :The crankshaft S is inserted in the machine by withdrawing the center 13 by the foot lever 56 until the work has been located between the centers, after which the foot lever is released, permitting the tail center 43 to engage the shaft S and toforce it firmly against the head center 41.

As the head spindle 26,; is thereafter rotated, the shaft is driven by the drive pin 12 and is reciprocated axially from the crankpin (56, the amount of such reciprocation being conveniently adjustable. Before the shaft is set in rotation, the different pairs of lapping members 112 and 113 are clamped about the different crankpins P and also, if desired, about the different main bearings M. The series of depending arms 84 and holders 91 on the rear shaft 7 7 and on the forward shaft 88 are commonly identical and may be used interehangably for lapping the crankpins P and the bearings M, provided the lapping members are of the right diameter.

In setting up for a new shaft, each hub 85 is adjusted along its bushing so as to bring its lapping members 112 and 113 in mid position lengthwise ofits crankpin or main bearing when the spindle 26 is at the middle point of its axial reciprocation. The length of the reciprocation is also adjusted to correspond to the length of the crankpins and the width of the lapping members upon the main bearings is so proportionedto the length of the main bearings that these bearings also will be completely traversed by the axial reciprocation of the crankshaft.

The lapping members are clamped against the crankpins and main bearings by throwing forward the toggle levers 108,-which positively lock the lapping members against the surfaces to belapped. The pressure of the laps upon the different crankpins and bearings may be adjusted and equalized by means of the adjusting swivel studs 120. The lapping members 112 and 113 are commonly of cast iron and it will be understood that a suitable lapping compound is applied to the faces of the lapping members before they are clamped in position.

After all of the lapping members are positioned and the pressure thereof is adjusted, the shaft is set in rotation and all of the crankpins and, if desired, the main bearings also, are simultaneously lapped and given an accurate cylindrical finished surface. It will be noted that the relative reciprocation of the crankpin and lap member, being caused by a crank element geared to the main driving shaft and a seriesof linkstherefor, will provide a substantially dead center at each end of the patlrof travel of the lapping'members and thus provide a limited dwell of the lapping members at these points. By this 1 operation all of the crank shaft and main bearings of a crankshaft may be accurately finished in a very short space of time. Commonly only a minute or so is required to bring the hearings to the desired condition. It will also be understood that when the machine is once adjusted for a given type and size of crankshaft, practically no adjustments are necessary in grinding successive crankshaftsof the same kind.

The number of teeth in the driven sprocket 7 0' (Fig. 3) is commonly selected so that it is not an even multiple of the number of teeth in the driving sprocket 73. In this way the reciprocations of the crankshaft do hot correspond to any exact number of complete rotations thereof, and a given axial position of the laps does not correspond to the same angular position of the crankshaft twice during the length of run commonly required for finishing the shaft. In this way the wear of the laps is distributed and a uniform size and finish is secured.

Having thus described my invention and the advantages thereof I do not wish to be limited to the details herein disclosed otherwise than asset forth in the claims, but what I claim is i 1. A crankshaft lapping machine comprising a plurality of crankpin-engaging laps, holders supporting said laps for movement thereof in a circular path with said crankpins but preventing rotation thereof, means to support a crankshaft-for rotation on its own axis with its pins engaged by said laps, means to rotate said shaft, and means to give said shaft limited axial reciprocation relative to said laps during the lapping operation, said reciprocating and said rotating means operat- .ing in positive fixed relation by which each complete period of reciprocation of said crankshaft corresponds to no com lete number of rotations of said cranksha t.

2. A crankshaft lapping machine comprising a plurality of crankpin-engaging laps,

hblders therefor, arms pivotally connected to said holders and supporting the remote ends thereof for swinging movement with said arms but preventing rotation thereof, a cross shaft fixed in said machine and pivotally supporting said arms, bushings for said arms on which said arms are axially adjustable and means to secure said bushingsfor free rotation in fixed axial position on said cross shaft.

3. A crankshaft lapping machine comprising means to support a crankshaft for rotation on its main'axis, means to rotate said shaft, a plurality of depending arms of greater effective length than the radius of the path of movement of the crankpins and pivoted to swing about an axis parallel to said main axis, a lap holder pivoted to each depending arm,

. an a pairof arcuate lapping members mounted in each holder and adapted to engage a crankpin or hearing of said shaft and means;

to give the crankpins a limited reciprocating movement, said dependlng arms and said lapping members being held from axialmove- ,ment during such reciprocation of the crankshaft. p

4. In a crankshaft lapping machine, a pair .of arcuate lapping members, toggle actuated means to positively snap said members about a crankpin, means to rotate the crankshaft about its main axis while thus engaged, and

of arcuate lapping members, and positive means to clamp said members about a crankpin, one of said members having a swivel mounting permitting self adjustment of said member to the crankpin surface.

6. In a crankshaft lapping machine, a pair of arcuate lapping members, and toggle actuated means to positively clamp said members about a crankpin, said members having recessed lapping surfacesto equalize the lapping action throughout the length of the hearin to be lapped.

I. In a crankshaft lapping machine, a pair of arcuate lapping members, toggle actuated means to positively clamp said members about a crankpin, and means to cause relative axial reciprocation between said lapping members and said crankpin.

8. In a crankshaft lapping machine, a pair of arcuate lapping members, and positive means to clamp said members about a crankpin, one of said lapping members being swivelled to the supporting means, and the other lapping member being mounted in said supporting means for movement about an axis radial to the crankpin.

9. In a crankshaft lapping machine, a depending arm, a pivotal support for said arm, a lap holder pivoted to said arm, clamping levers carried by said holder, lapping members mounted at the ends of said levers, and means to positively lock said levers with said lapping members in operative position.

10. In a crankshaft lapping machine, a depending arm, a pivotal support for said arm,

a lap holder pivoted to said arm, clamping levers carried by said holder, lapping members mounted at the ends of said levers, a pair of toggle links connecting the opposite ends of said levers, and means to move said links to positively lock said members in lapping pos1t1on.

11. In a crankshaft lapping machine, a shaft, an arm pivoted thereto, a pair of arcuate lapping members pivoted to said arm, a crank pin supported in said machine, and positive. means to clamp said members about said crankpi'n, the adjacent edges of said members being substantially spaced apart when said members are in lapping position.

121. A crankshaft lapping machine comprising means to support a crankshaft forrotation on its main axis, means to rotate said shaft,="a plurality of depending arms pivoted to swing about an axis parallel to said main 13. A crankshaft lapping machine comprising means to support a crankshaft for rotation on its main axis, means to rotate said shaft, a plurality of arms pivoted to swing about an axis parallel to said main axis, a lap holder pivoted to each arm, and a pair of lapping members mounted in each holder and adapted to engage a crankpin or bearing of said shaft.

14. In a crankshaft lapping machine, a plurality of arcuate lapping members, and positive means to clamp said members about'a crankpin, certain of said members having a mounting effective to permit self-adjustment of said members relative to the crankpin surface.

15. A crankshaft lapping machine comprising a plurality of crankpin-engaging laps,

holders supporting said laps for movement in circular paths with said crankpins but preventing rotation thereof, means supporting the remote ends of said holder for movement in predetermined paths transversely to the axis of the crankshaft, means to support the crankshaft for rotation on its own axis with its crankpins engaged by said laps, means to rotate said crankshaft, means to hold said laps rigidly against separation during the lapping operation, and means permitting swivelling movement of certain of said laps relative to their associated laps.

In testimony whereof I have hereunto affixed my signature.

SYDNEY PLAYER. 

